Can I make this dish without a mandoline?

Yes, you can slice the potatoes by hand, but try to maintain an even thickness (about 1/8 inch) so they cook evenly. A sharp chef's knife works well, just take your time for consistency.

Why did my cheese sauce turn out grainy?

Grainy cheese sauce usually happens when the heat is too high or the cheese is added all at once. Make sure to remove the sauce from heat before adding cheese, and consider using a cheese with better melting properties like medium cheddar if you continue to have issues.

Can I prepare the fried onions in advance?

Absolutely! Fried onions can be made up to 2 days in advance. Store them in an airtight container at room temperature with a paper towel to absorb any extra moisture. They may lose some crispness but will still be delicious.

What's the difference between scalloped potatoes and au gratin potatoes?

Traditionally, scalloped potatoes are made with a cream sauce while au gratin potatoes include cheese in the dish and sometimes breadcrumbs on top. This recipe is technically a hybrid, as it includes cheese like an au gratin but has the layered presentation of scalloped potatoes.

Fried Onion Scalloped Potatoes Recipe

This incredible Fried Onion Scalloped Potatoes dish transforms humble ingredients into a masterpiece of comfort food. Layers of perfectly tender potatoes swimming in a rich, creamy cheese sauce, all crowned with crispy, golden fried onions that add the perfect textural contrast. It’s remarkably simple to prepare but delivers restaurant-quality results that will have everyone at your table asking for seconds. Perfect for holiday gatherings, Sunday dinners, or anytime you want to elevate a weeknight meal!

Why You’ll Love This Recipe

Irresistible Texture Combination: The contrast between the creamy, tender potatoes and the crispy fried onions creates a textural masterpiece that keeps you coming back for more.
Make-Ahead Friendly: This dish can be partially prepared in advance, making it perfect for busy days or special occasions when you want to minimize last-minute cooking.
Crowd-Pleaser: Everyone from kids to grandparents will love this dish – it’s classic comfort food with a gourmet twist that impresses without being pretentious.
Versatile Side Dish: Pairs beautifully with everything from holiday roasts to simple weeknight chicken – it’s the side dish that often becomes the star of the meal.

Ingredients You’ll Need

Russet Potatoes: The starch content makes them perfect for scalloped potatoes, creating that ideal creamy-yet-structured texture when baked.
Butter: Forms the base of your roux, adding richness and helping create the velvety sauce.
All-Purpose Flour: Works with butter to create a roux that thickens your cheese sauce to the perfect consistency.
Whole Milk: Provides creaminess and body to the sauce – stick with whole milk for the best texture.
Sharp Cheddar Cheese: Brings a fantastic flavor depth that mild cheese simply can’t match – the sharpness balances beautifully with the creamy sauce.
Yellow Onions: Transform into sweet, crispy flavor bombs when fried – they’re what makes this recipe special.
Vegetable Oil: Choose a neutral oil with a high smoke point for perfectly crispy onions without any off flavors.
Salt and Pepper: Essential for bringing all the flavors to life – don’t skimp on proper seasoning.
Parsley: Adds a fresh pop of color and subtle herbaceous note to finish the dish.

Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

Different Cheese Options

Experiment with different cheese combinations! Try mixing in some smoked gouda for depth, Gruyère for nuttiness, or pepper jack for a spicy kick. You can even do a blend of three or four cheeses for a complex flavor profile.

Herb Infusions

Add fresh thyme or rosemary to the cheese sauce for an aromatic twist. About 1-2 teaspoons of chopped fresh herbs will infuse the entire dish with wonderful flavor.

Add Some Protein

Transform this side into a complete meal by adding layers of thinly sliced ham or crumbled cooked bacon between the potato layers.

Make It Garlicky

Add 2-3 minced garlic cloves to the butter before making the roux for a delicious garlic undertone throughout the dish.

How to Make Fried Onion Scalloped Potatoes

Step 1: Prepare the Base

Preheat your oven to 375°F and spray a 9×13-inch baking dish with cooking spray. This prevents sticking and makes serving and cleanup much easier.

Step 2: Create the Cheese Sauce

Melt butter in a medium saucepan over medium heat. Whisk in flour, salt, and pepper to create a roux, cooking for about a minute until it smells slightly nutty. Slowly drizzle in room temperature milk while constantly whisking to prevent lumps. Continue cooking and whisking frequently until the mixture thickens noticeably, about 5-8 minutes. You’ll know it’s ready when it coats the back of a spoon.

Step 3: Add Cheese to the Sauce

Remove the saucepan from heat and stir in 1 cup of shredded cheese. Continue stirring until completely melted and smooth, which should take less than a minute. Set this luscious cheese sauce aside.

Step 4: Arrange the Potatoes

Carefully arrange your thinly sliced potatoes in the prepared baking dish, trying to keep them somewhat together as you fan them out in a single layer. This arrangement helps ensure even cooking and creates a beautiful presentation.

Step 5: Add Sauce and Cheese

Pour your cheese sauce evenly over the arranged potatoes, making sure to get into all the nooks and crannies. Sprinkle the remaining cup of shredded cheese over the top for that perfect golden crust.

Step 6: Initial Bake

Cover the dish with aluminum foil and bake for 50 minutes. The foil prevents the top from browning too quickly while allowing the potatoes to steam and become tender.

Step 7: Finish Baking

Remove the foil and continue baking for about 10 more minutes, or until the potatoes are perfectly fork-tender and the top is bubbling and golden.

Step 8: Prepare the Fried Onions

While the potatoes are baking, prepare your fried onions. Line a large baking sheet with two layers of paper towels to absorb excess oil. Heat vegetable oil to 350°F in a large saucepan. Working in 1-cup batches, fry the sliced onions until they turn a pale golden brown, about 2-5 minutes per batch. Use a mesh strainer or slotted spoon to transfer fried onions to the paper towels. Sprinkle with salt while still warm.

Step 9: Add Onion Topping and Serve

Sprinkle the fried onions evenly over the finished scalloped potatoes. Garnish with fresh parsley and serve hot, adding additional salt and pepper to taste if needed.

Pro Tips for Making the Recipe

Use a Mandoline: For evenly sliced potatoes that will cook at the same rate, a mandoline is invaluable. Just be sure to use the guard to protect your fingers!
Room Temperature Milk: Using room temperature milk instead of cold prevents the sauce from seizing and creates a smoother result.
Oil Temperature Matters: Keep a close eye on your oil temperature when frying the onions. Too hot and they’ll burn quickly; too cool and they’ll absorb oil and become greasy.
Don’t Rush the Sauce: Take your time developing the cheese sauce. Rushing can result in a grainy or lumpy texture that’s hard to fix later.
Rest Before Serving: Let the dish sit for 5-10 minutes after removing from the oven. This helps the sauce set slightly and makes serving easier.

How to Serve

Perfect Pairings

These scalloped potatoes shine alongside roasted meats like prime rib, ham, or a simple roast chicken. The creamy potatoes complement the proteins beautifully.

Complete the Meal

Add a bright, acidic side like a vinaigrette-dressed salad or roasted Brussels sprouts with balsamic glaze to balance the richness of the potatoes.

Beverage Suggestions

Pair with a crisp white wine like Chardonnay or Sauvignon Blanc to cut through the creaminess, or a light beer for casual gatherings.

Make Ahead and Storage

Make Ahead Options

Prepare the entire dish up to the point of baking, cover tightly with foil, and refrigerate for up to 24 hours. When ready to bake, allow it to sit at room temperature for 30 minutes before following the baking instructions. You may need to add 5-10 minutes to the covered baking time if the dish is still cold.

Storing Leftovers

Store cooled leftovers in an airtight container in the refrigerator for up to 3 days. The onions will lose some crispness but will still be delicious.

Reheating

For best results, reheat individual portions in the oven at 350°F for about 15 minutes or until heated through. You can microwave in a pinch, but the texture won’t be quite the same. If you have extra fried onions stored separately, add them after reheating for maximum crispness.

Freezing

While you can freeze the potato portion without the fried onions for up to 2 months, the texture may change slightly upon thawing. Make fresh fried onions after reheating for best results.

FAQs

Can I make this dish without a mandoline?

Yes, you can slice the potatoes by hand, but try to maintain an even thickness (about 1/8 inch) so they cook evenly. A sharp chef’s knife works well, just take your time for consistency.
Why did my cheese sauce turn out grainy?

Grainy cheese sauce usually happens when the heat is too high or the cheese is added all at once. Make sure to remove the sauce from heat before adding cheese, and consider using a cheese with better melting properties like medium cheddar if you continue to have issues.
Can I prepare the fried onions in advance?

Absolutely! Fried onions can be made up to 2 days in advance. Store them in an airtight container at room temperature with a paper towel to absorb any extra moisture. They may lose some crispness but will still be delicious.
What’s the difference between scalloped potatoes and au gratin potatoes?

Traditionally, scalloped potatoes are made with a cream sauce while au gratin potatoes include cheese in the dish and sometimes breadcrumbs on top. This recipe is technically a hybrid, as it includes cheese like an au gratin but has the layered presentation of scalloped potatoes.

Final Thoughts

These Fried Onion Scalloped Potatoes elevate a classic comfort food to something truly special. The combination of creamy, cheesy potatoes with the irresistible crunch of homemade fried onions creates a dish that will have everyone at your table raving. Whether served for a holiday feast or a cozy family dinner, this dish brings warmth and satisfaction to any meal. Give it a try – I’m confident it will become a requested favorite in your recipe collection!